International Patent Publication WO 96/23595 (Melancon et al.) discloses a process, referred to as a carrier fluid process, for coating a composite layer onto a web. The composite layer comprises a carrier layer of fluid (such as water) and one or more functional layers (such as silicone or other polymeric materials). With subsequent removal of the carrier fluid layer, only the functional layer is left on the web. The advantage of this process is that it can be used to generate thin (i.e. less than 100 microns) and ultrathin coatings (i.e. less than 1 micron coatings) without solvent dilution.
U.S. Pat. No. 5,061,535 (Kreckel, et al.) discloses the generation of geometric patterns by flexographic or gravure printing.
The coating art also employs "Langmuir-Blodgett" type bath coaters such as described by K. Blodgett in Journal of the American Chemical Society, vol. 57 1935, p. 1007 and U.S. Pat. No. 4,093,757 (Barraud, et al 1978) and Japanese Patent Application 63-327260 (Masutani, etal 1990). In Langmuir bath coating, a functional layer, comprising a coating formulation is floated on the surface of a bath of water or another supportive (carrier) liquid and is then transferred to a substrate or web by dipping or rolling the substrate off of the bath surface.
Traditional methods of applying coatings to minimize coating defects are discussed in Cohen, E. D. and Gutoff, E. B., Modern Coating and Drying Technology, VCH Publishers, New York 1992 and Satas, D., Web Processing and Converting Technology and Equipment, Van Norstrand Reinhold Publishing Co., New York 1984.